Abstract: Clarifying the effects of exclosure on soil stoichiometric characteristics of wetland provides a theoretical basis for better understanding the influence of exclosure on wetland restoration. We chose swamp meadows and meadows with no grazing prohibition, exclosure for 3, 8 and 10 years in Napahai wetland to examine the effects of different exclosure durations on the contents and stoichiometry of carbon (C), nitrogen (N), and phosphorus (P). The results showed that exclosure enhanced the contents of soil total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), nitrate nitrogen (NO₃^--N), ammonium nitrogen (NH₄⁺-N), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and microbial biomass phosphorus (MBP), as well as C/N, C/P, N/P and MBN/MBP of swamp meadow and meadow. The C/N, C/P, and N/P of swamp meadow and meadow soil were positively correlated with TOC, TN, moisture content, NO₃^--N, NH₄⁺-N, MBN (P<0.01), but negatively correlated with bulk density. The MBC/MBN and MBC/MBP of swamp meadow soil was significantly negatively correlated with TOC, NH₄⁺-N, MBN, and moisture. MBN/MBP had no significant correlation with all environmental factors. The MBC/MBN, MBC/MBP of meadow soil were significantly negatively correlated with TOC, TN, MBN, and water content (P<0.01). MBN/MBP was significantly positively correlated with pH, MBN, water content (P<0.01). Soil TOC was the dominant factor affecting soil ecological stoichiometry in swamp meadow and meadow under exclosure. In conclusion, exclosure changes soil ecological stoichiometric characteristics of Napahai wetland by affecting nutrient conditions.

Key words: exclosure, ecological stoichiometry, swamp meadow, meadow, Napahai.